I am curious if it even makes consider BizTalk for the implementation of a pub/sub messaging architecture (basically what you can do with NServiceBus or MassTransit is all I rea
Biztalk is a broker and is more suited for EAI within the boundaries of different business services. A servicebus is fundamentally different. A comparison can be found here:
http://docs.particular.net/nservicebus/architecture/nservicebus-and-biztalk
If you can share some of your requirements I might be able to give some more guidance.